Thanks for that info, Mike, some interesting stuff. We bought our tree about 25 years ago from what was then a government experimental farm at Saittas. I believe the variety is Mohawk. I can't remember at what age it began to produce nuts but it has never failed to give a good crop every year, until this one. I know it is self-fertile as it is the only one in this area, the nearest ones being way over the other side of the village, probably a couple of miles away. The only suggestion I can come up with is similar to what you say, that the unusual weather pattern has somehow thrown its pollen shedding and pollen receptivity out of sync. We'll just have to wait and see what happens next year. In the meantime no nuts for Christmas!!